GM Crops, Climate Change and Protecting the Environment: The Latest Research

According to a recent report by the Intergovernmental Panel on Climate Change (IPCC), greenhouse gas emissions (GHGs) associated with land use account for somewhere between 21-37% of all anthropogenic emissions. Agriculture is the main culprit, both as a cause of deforestation and as a major emitter of GHGs, especially carbon dioxide, nitrous oxide, and methane. Agriculture is also destroying biodiversity and pushing all sorts to species to the brink of extinction. If that’s not bad enough, the UN’s Food and Agriculture Organization is predicting a future characterized by increasing scarcity, diminishing quality of land and water resources, and persistent food insecurity – if food and agricultural systems remain on their current path.

What to do? In brief: produce more food on less land, decrease emissions and other “negative externalities” associated with farming (e.g., pesticide and fertilizer spillover), reduce food waste, eat less beef, limit using grains for biofuels, and return as much land as possible to wild habitat. A tall order.

Pace the GMO-doubters, genetically modified crops can help in this Herculean task. Here’s how one farmer put it:

“As an Iowa farmer reading these articles which claim biotech crops don’t increase yields or benefit the environment, nothing I see here matches my experience or the experience of the other farmers I know who are reaping the benefits of this technology…Anyone who is familiar with GM seeds knows the environmental and economic benefits of the technology. When I first began farming, we used large amounts of broad based herbicides and pesticides, and today’s technologies are safer and cleaner for the environment and for farmers. Yields have increased and we’re better able to battle the elements, weeds, pests, and viruses. Healthier plants have meant greater yields, which has translated to more income for myself and other biotech farmers.” - Quoted by Val Giddings Fact-Checking The New York Times on Genetically Modified Crop Yields November 9, 2016

Ok, now let’s look at some recent research findings. To quote a bunch of them:

“This paper updates previous assessments of important environmental impacts associated with using crop biotechnology in global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops since their first widespread commercial use in the mid-1990s. The adoption of GM insect resistant and herbicide tolerant technology has reduced pesticide spraying …[and] has also facilitated important cuts in fuel use and tillage changes, resulting in a significant reduction in the release of greenhouse gas emissions from the GM cropping area. In 2015, this was equivalent to removing 11.9 million cars from the roads.” - Brookes and Barfoot (2017) Environmental impacts of genetically modified (GM) crop use 1996–2015: Impacts on pesticide use and carbon emissions

“When pesticides are weighted by the environmental impact quotient, however, we find that (relative to nonadopters) GE adopters used about the same amount of soybean herbicides, 9.8% less of maize herbicides, and 10.4% less of maize insecticides. In addition…for both soybean and maize, [GE] adopters used increasingly more herbicides relative to nonadopters, whereas [GE maize adopters] used increasingly less insecticide.” - Perry, Ciliberto, et al. (2016) Genetically engineered crops and pesticide use in U.S. maize and soybeans

“This annual updated analysis shows that there continues to be very significant net economic benefits at the farm level…These gains have been divided 49% to farmers in developed countries and 51% to farmers in developing countries. About 72% of the gains have derived from yield and production gains with the remaining 28% coming from cost savings. The technology has also made important contributions to increasing global production levels of the 4 main crops [soybeans, corn, cotton and canola]”. - Brookes and Barfoot (2017) Farm income and production impacts of using GM crop technology 1996–2015

Transgenic plants containing Bacillus thuringiensis (Bt) genes are being cultivated worldwide to express toxic insecticidal proteins…. Various experimental studies have been made worldwide during the last 20 years to investigate the risks and fears associated with non--target organisms [which] include beneficial insects, natural pest controllers, rhizobacteria, growth promoting microbes, pollinators, soil dwellers, aquatic and terrestrial vertebrates, mammals and humans. To highlight all the possible risks associated with different GM events, information has been gathered from a total of 76 articles, regarding non--target plant and soil inhabiting organisms, and summarised in the form of the current review article. No significant harmful impact has been reported in any case study related to approved GM events…- Yaqoob, Shahid, et al. (2016). "Risk assessment of Bt crops on the non-target plant-associated insects and soil organisms"

Bottom line: overall, GM crop technology reduces emissions, insecticide use, and the amount of land needed to produce a given yield. GM technology shows promise as a tool to improve drought tolerance. GM crops have provided significant economic benefits to farmers and consumers in both developed and developing countries. Some GM crops may improve soil health and biodiversity (mainly by reducing use of insecticides). The verdict isn’t quite so favorable regarding herbicides, i.e., weed killers. In some cases, GM technology encourages over-application of herbicides. But there are other ways to address herbicides: a new precision technology has come out that promises to slash herbicide use, one that doesn’t required genetically modified organisms or chemicals. And the farmers are lining up. Next

Coupe, R. H. and P. D. Capel (2016). "Trends in pesticide use on soybean, corn and cotton since the introduction of major genetically modified crops in the United States." Pest Management Science 72(5): 1013-1022 https://doi.org/10.1002/ps.4082